1. Field of the Invention
This invention concerns ignition systems in general, and particularly ignition systems as applied to a fuel injection type of internal combustion engine. More specifically, it relates to an ignition system for a piston type of internal combustion engine as contrasted with a turbine type.
2. Description of Prior Art
While prior attempts have been made to eliminate the need for a distributor in an ignition system of the type employed by a piston type internal combustion engine, all known attempts have had various difficulties including the specialized nature of the elements employed, and the practicability of carrying out the concepts. For example, there is an old U.S. Pat. No. 1,335,933 to Bohli issued Apr. 6, 1920, which purports to eliminate the distributor, but which operates by separating the electrical paths of spark current by using rectifiers for this purpose. It employs only a single high voltage coil for generating the high potential needed to create the sparks at the spark plugs, and it appears doubtful that the desired effect for distributing the sparks would be obtainable.
Another prior attempt was suggested by a patent to June U.S. Pat. No. 2,002,114 issued May 21, 1935. That patent makes use of special spark plugs with a single electrode so that the other electrode for spark generation becomes the piston as the engine is operated. The system generates sparks at two of the cylinders simultaneously, one of which is on the compression stroke while the other is on the exhaust stroke. However, the other two cylinders have a large distance between the spark plug electrodes and the pistons, so that no sparks are created there. Again in this case, there is only a single vibrator coil which supplies the high voltage potential to the spark plugs.
Another attempt was suggested by the Patent to Grow U.S. Pat. No. 2,324,923 issued July 20, 1943. This patent employs specially constructed spark plugs and uses solenoids to move one of the electrodes for creating a spark gap at the time when a spark is desired at that cylinder.
Also, there are two patents to Short U.S. Pat. Nos. 2,436,905 issued Mar. 2, 1948 and 2,456,743 issued Dec. 21, 1948. The approach used in these patents is to provide individual tuned circuits at the spark plugs while connecting an oscillator output to them all with a variation in the frequency of the oscillator. Thus, each spark is generated when the oscillator frequency matches that of the tuned circuit at a particular spark plug.
In contrast to the aforementioned attempts to eliminate a distributor, the applicant has as an object of the invention the provision of a system for generating sparks simultaneously at all of the spark plugs of a piston type internal combustion engine. The engine, of course, must be a type that has a combustible mixture in only one cylinder at a time.